Researchers at Columbia University Law School Addressed this well in their paper: “Rebutting 33 False Claims About Solar, Wind, and Electric Vehicles“. Here’s what they had to say:
Forests have immense ecological benefits, recreational benefits, and intrinsic value. However, when looking at the narrow but important issue of carbon accounting, it is usually not true that removing trees to build a solar farm negates any emissions reductions from solar generation. In fact, an acre of solar panels in the United States usually offsets significantly more carbon dioxide emissions than an acre of planted trees can sequester.
In the United States, the emissions intensity of electricity produced by natural gas-fired power plants is roughly 1,071 pounds of carbon dioxide per megawatt-hour (MWh).
The emissions intensity of solar PV, meanwhile, is about 95 pounds per MWh, a difference of 976 pounds per MWh compared to natural gas. According to a 2022 Journal of Photovoltaics study, utility-scale solar power produces between 394 and 447 MWh per acre per year. When displacing electricity from natural gas, an acre of solar panels, producing zero-emissions electricity would therefore save between 385,000 to 436,000 pounds, or 175 to 198 metric tons, of carbon dioxide per year.
By comparison, according to the EPA, an average acre of U.S. forest sequesters 0.857 metric tons of carbon dioxide per year. Thus, an average acre of solar panels in the United States reduced approximately 204–231 times more carbon dioxide per year than an acre of forest. Furthermore, while removing trees from forests releases stored carbon, such emissions can be offset by solar energy generation and the resulting reduction in fossil fuel-driven emissions.
The EPA has estimated the average acre of forests contains 83 metric tons of carbon, and approximately half of that amount is sequestered in soil. Even assuming that all 83 metric tons of carbon (comprising 304 metric tons of carbon dioxide) were released when building a solar farm on an acre of forested land, those emissions could be offset within two years of operation of a typical solar farm. Finally, to put the threat to forests in context, only about 4% of solar projects in the United States are being sited on currently-forested lands.
Resources
National Renewable Energy Laboratory, Life Cycle Greenhouse Gas Emissions from Electricity Generation: Update (Sept. 2021) (Table 1), https://www.nrel.gov/docs/fy21osti/80580.pdf.
Mark Bolinger and Greta Bolinger, Land Requirements for Utility-Scale PV: An Empirical Update on Power and Energy Density , 12 IEEE J. VOLTAICS 589, 593 (2022), https://www.doi.org/10.1109/JPHOTOV.2021.3136805.
Greenhouse Gas Equivalencies Calculator – Revision History , U.S. ENV’T PROT. AGENCY, https://www.epa.gov/energy/greenhouse-gas-equivalencies-calculator-revision-history
Greenhouse Gas Equivalencies Calculator – Calculations and References , U.S. ENV’T PROT. AGENCY, https://www.epa.gov/energy/greenhouse-gases-equivalencies-calculator-calculations-and-references
L. Kruitwagen et al., A Global Inventory of Photovoltaic Solar Energy Generating Units, 598 Nature 604 (October 2021) https://doi.org/10.1038/s41586-021-03957-7.